Hey, I heard it was for adjusting mixture . Right?? Just kidding...No, it's the idle adjustment. But when I was first building mine it did not do anything. With further reading here I found out it was a possible air leak. So once I installed a new intake gasket it started to work the way it was supposed to.
Downloaded some pics I replaced the gasket thanks man. I think that is what it was can not wait untill the morning. to test it out maybe mine was leaking too. There was a big tear in it and the gasket was as thin as tissue paper. I put blue silicone junk on it too RTV and lock tite on the nuts.
I cut some automotive gasket making material. If anything it will be better than before. Let you know how it works tomorrow. Thanks Blastove. I already sealed up the carb end thanks to hints from other guys.
I've flattened my intake manifold also as it was quite curved and letting in air. One thing that wondered when I was doing up the nuts was if the threaded rod is too long then the dome nuts would only tighten up so far and the gasket would not actually be compressed enough.
I am considering replacing the dome nuts with standard ones to see if this helps.
I know on the head of the motor that each threaded rod is a different height and when built by the manufacturer they used a different number of washers under each nut to get the correct height. I will also be using standard nut on the head soon.
One other thing that is on my Yamaha motocross bike is copper washers under the head nuts. I don't know exactly why they use copper but I am guessing it expands with the heat faster and therefore tightens the nut. It does not have a lock washer but always keeps tight. I will be installing copper washers soon so will if their are any problems I will post it here.
Not sure if using copper washers on the inlet and outlet manifolds would be good?
Should have checked my intake manifold for being straight. I did notice that it was shiny chrome though. should have roughened up the chrome with a fine file or sand paper, and mad sure it was flat with a file.
moddy edit: two topics for 1 carb?
My carb spring does not spring back like it is supposed to. That metal thing that the spring pushes up and down bindes and does not go up and down smoothly like it is supposed to does not spring back. Any ideas. I thought about sanding it down so it is smoother. I have tried putting oil on it. It seems like I have posted this before, but I can not find it.